Method and product for extruding materials that exhibit anisotropic properties by means of reciprocating die surfaces

Abstract

Two movable die members that are situated opposed to each other in an extrusion die assembly, the axis of movement of the two die members is parallel to the longer sides of the rectangular cross-section of a throat opening of the extrusion die assembly. The members move in a reciprocating back and forward movement to impart shearing forces to the surface of the extruded material with a resultant multiaxial orientation of the molecules or fibrils.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is as follows: 
     
       1. A method for extruding a material that is comprised of molecules or fibrils that exhibit anisotropic properties due to molecular or fibril orientation along a single axis as a result of the extrusion process, comprising the steps of: forcing the material to be extruded in a liquid state through a die in which an upper planar die surface moves in a first direction transverse to the direction of material flow through the die and a low planar die surface moves in a direction opposite said first direction; and   changing the direction of movement of said upper a lower surface at determined time intervals.   
     
     
       2. A method as recited in claim 1 further including the step of moving said material in a direction transverse to the flow direction by means of teeth situated on said die surfaces. 
     
     
       3. A method for making a multilayer circuit substrate, using a polymer, such as a liquid crystal polymer, a ceramic, or composite material that is comprised of molecules or fibrils that exhibit anisotropic properties due to molecular or fibril orientation along a single axis as a result of the extrusion process, comprising the steps of: forcing the material to be extruded in a liquid state through a die in which an upper planar die surface moves in first direction transverse to the direction of material flow through the die and a lower planar die surface moves in a direction opposite said first direction; and   changing the direction of movement of said upper and said lower surface at determined time intervals;   metallizing the sheet;   patterning a resist on the metallized sheet;   etching the metallized sheet to form a conductive pattern;   forming vias in the metallized sheet;   adding solder to the vias for connectivity; and   blanking the layers.   
     
     
       4. An extruded material in which the molecules or fibrils of the material are oriented during the extrusion process in a pattern that is undulating in the direction of material flow during the extrusion process. 
     
     
       5. An extruded material as in claim 4, in which the undulating fibril or molecular orientation changes direction from a top surface of the material to a bottom surface of the material. 
     
     
       6. An extruded material as in claim 5, wherein the undulating fibril or molecular orientation at the top surface is in a direction opposite the fibril or molecular orientation at the bottom surface.